陶瓷膜-粉末活性炭组合工艺模拟处理污水过程中膜污染的介电监测

Dielectric monitoring of membrane fouling during simulated treatment for polluted water by ceramic membrane-powdered activated carbon suspension

利用介电弛豫谱(DRS)方法实施了对陶瓷膜-活性炭组合工艺处理污染饮用水过程的模拟研究,发现由介电参数表征的膜-"污水"之间的界面极化会强烈地受液相中活性炭浓度影响:随着活性炭浓度的增大,原本的膜-液间的界面极化向污垢层/污水形成的新的界面极化转化——显示了膜污染的发生,活性炭浓度超过0.3g/L时,污染变得显著,而且此膜污染过程和膜运行时间的关联性可以用污垢层、膜、污染液三相电参数来表征.可以通过测量介电参数和解析获得的污垢层相的电参数,完成对模拟陶瓷膜污染过程实时监测;对于本研究的平板陶瓷膜-活性炭(腐植酸)悬浮液体系,最佳运行时间为1h.本研究表明,通过定量的模型化介电解析,实施对组合工艺中陶瓷膜的污染监测是可行的.

The process of simulated treatment for polluted water by ceramic membrane-powdered activated carbon suspension was studied bY dielectric relaxation spectroscopy （DRS）. Dielectric parameters show that the interracial polarization between membrane and polluted water is strongly influenced by the concentration of activated carbon. With the increase of activated carbon concentration, the interracial polarization between membrane and polluted water turns into the interracial polarization between fouling layer and polluted water, suggesting the occurrence of membrane fouling. When the activated carbon concentration exceeds 0. 3 g/L, the fouling becomes significant. Besides, the relevance of membrane fouling and running time of the treatment process can be characterized by the electrical parameters of fouling layer, membrane and contaminating fluid. Thus it is concluded that the fouling process of ceramic membrane can be monitored in real time by the measured dielectric parameters and electrical parameters of fouling layer obtained by dielectric analysis. For the flat ceramic membrane-activated carbon （corrosive acid） suspension system in this work, the optimum operating time is about I h. This study shows that the quantitative modeling dielectric analysis is feasible to monitor the fouling of ceramic membrane in combined process.